The present application relates to motor grader controls and in particular, relates to motor grader controls which are more intuitive to operate.
Motor graders are relatively complicated and require considerable operator skill to fully utilize the capabilities of the machine. Traditionally, the various components of the grader are controlled by manual shift levers which are associated with hydraulic control valves for adjusting hydraulic components. These control levers are typically mounted for movement in the fore and aft direction of the motor grader.
Mechanical control systems of this type are most common, however, there has been concern with respect to operator fatigue and the actual operator movement necessary to actuate the hydraulic components.
More recently, it has been proposed to use joy stick type controllers for controlling the various functions of the motor grader. Unfortunately, the controller becomes quite complicated and is not intuitive with respect to the operation of the grader.
The present invention seeks to overcome a number of these difficulties and provide a control arrangement which is more intuitive with respect to the components being controlled.
The present invention provides an operator control arrangement for controlling a blade suspended beneath the frame of a grader and moveable beneath the frame of the grader to various adjusted positions by means of at least a blade lift arrangement, a blade rotation arrangement and a blade slide arrangements. The operator control arrangement comprises a miniature representation of a motor grader blade support arrangement which controls the position of the blade of the motor grader. The miniature representation is controlled by one hand of the operator and includes a visually identifiable blade representation which is moveable in a sliding manner and controls the slide movement of the blade. This blade representation is also rotatable about a normally vertical axis and controls the angle of the blade relative to the grader frame. The blade representation also controls high lift cylinders of the grader blade by moving of the visually identifiable blade representation in a vertical plane to sense the desired direction of adjustment of the high lift cylinders of the motor grader.
With this control arrangement, the operator adjusts the position of the blade of the motorgrader by adjusting the position of the miniature representation of the motor grader support arrangement which allows the operator to impart the direction of change to the component of the blade support arrangement.
In an aspect of the invention, the miniature representation is universally pivoted at a forward end by means of an elongate member which corresponds to a draw bar of the motor grader.
In a further aspect of the invention, the operator control arrangement is biased to a neutral position and movement of the control out of the neutral position requires the operator to exert a force to overcome the bias and thereby initiate adjustment of the grader blade in the direction of the force. The control arrangement returns to the neutral position upon removal of the exerted force.
In yet a further aspect of the invention, the control arrangement has the blade representation slidable beneath a ring gear representation which is pivotally secured to the elongate member and is movable about the pivot in a first direction to initiate rotation of the ring gear in a first direction and movable about the pivot in the opposite direction to initiate rotation of the ring gear in a direction opposite to the first direction of the ring gear movement.
In yet a further aspect of the invention, the control arrangement includes two position sensing links either side of the elongate member which correspond to high lift cylinders of the blade lift arrangement. The position sensing links sense movement of the ring gear representation to adjust the height of the ring gear and the angle of the ring gear of the representation. In this way, both high lift cylinders can either extend or retract together, or one high lift cylinder can be extended while the other high lift cylinder is contracted.
In yet a further aspect of the invention, movement of the control arrangement from the neutral position closes at least one switch which causes at least one hydraulic member of the blade support arrangement to adjust the position to the blade support arrangement in a sympathetic manner and direction.
In yet a further aspect of the invention, movement of the control arrangement can simultaneously initiate movement of the blade, said high lift cylinders and said ring gear.
The miniature representation is based on a neutral position and senses the direction of change being imparted by the operator when the miniature representation is moved from the neutral position. The actual amount of representation is relatively small as it is only sensing the direction of movement rather than the actual position of the blade support arrangement. The miniature representation is directly related to the actual blade support arrangement and as such the actual operator quickly understands the control. Preferably this miniature representation is secured to the operator chair adjacent one arm of the operator chair such that the arm of the operator is supported during use of the control. As can be appreciated, the one hand control with experience can impart a movement to the control which will adjust many of the hydraulic components of the actual blade lift support arrangements. The control arrangement has a dead region about the neutral position and the operator must move the representation out of the neutral position to effect the adjustment of the blade support arrangement.
In yet a further aspect of the invention, a miniature representation of the grader frame with the front wheels is provided at the opposite arm of the operator chair. This miniature representation includes two front wheels which can be steered as well as angled to correspond to the operator controls for the front steering. The operator can steer the grader by turning the front wheels as required to impart a turning direction and also angle the front wheels as desired to control the operational characteristics of the grader.
In a preferred aspect of the invention, the steering control representation also includes a release button which allows movement of the representation of the grader frame from a neutral position to control the articulation of the grader frame. The use of a release button is preferred to ensure the operator desires this feature to be initiated.
In a preferred aspect of the blade support arrangement, there is also a release button associated with the draw bar which when activated allows the draw bar to be shifted from side to side. This corresponds to a side shift control of the ring gear and allows movement of the ring gear beneath the actual grader frame from side to side in accordance with the direction imparted by the operator. Again, the release button ensures the operator desires to exercise this particular control over the blade lift arrangement.